We have now completed studies showing that prophylactic treatment with granulocyte colony-stimulating factor (G-CSF) reduces endotoxemia and serum tumor necrosis factor levels, and improves cardiovascular function and survival with both Escherichia coli peritonitis and pneumonia in canine models. To determine whether prophylactic G-CSF would have similar effects with intravascular E. coli infection, we have investigated the effects of pretreating canines with G-CSF before E. coli infusion. The experiments for this study have been completed, and data are being analyzed.